Add ability to parse multiple packets and move polyfills (#7)

Add ability to parse multiple packets and move polyfills

Author: codetheweb

package-lock.json

@@ -25,7 +25,7 @@
     "babel-cli": "6.26.0",
     "babel-preset-env": "1.7.0",
     "eslint-config-xo-typescript": "0.19.0",
-    "husky": "3.0.7",
+    "husky": "3.0.8",
     "typescript": "3.6.3",
     "xo": "0.25.3"
   },

package.json

@@ -1,9 +1,3 @@
-// Polyfills
-/* eslint-disable import/no-unassigned-import */
-import 'core-js/stable';
-import 'regenerator-runtime/runtime';
-
-// Application
 import {EventEmitter} from 'events';
 import {Socket} from 'net';
 import debug from 'debug';
@@ -162,32 +156,34 @@ class Device extends EventEmitter implements Device {
   private _handleSocketData(data: Buffer): void {
     this._log('Received:', data.toString('hex'));
 
-    const frame = this._messenger.decode(data);
-
-    // Emit Frame as data event
-    this.emit('data', frame);
-
-    // Check if it's a heartbeat packet
-    if (frame.command === COMMANDS.HEART_BEAT) {
-      this._lastHeartbeat = new Date();
-      return;
-    }
-
-    // Atempt to convert to JSON
-    let parsedData;
-
-    try {
-      parsedData = JSON.parse(frame.payload.toString('ascii'));
-    } catch (_) {
-      // Not JSON data
-      return;
-    }
-
-    if ('dps' in parsedData) {
-      // State update event
-      this._state = {...this._state, ...parsedData.dps};
-      this.emit('state-change', this._state);
-    }
+    this._messenger.splitPackets(data).forEach(packet => {
+      const frame = this._messenger.decode(packet);
+
+      // Emit Frame as data event
+      this.emit('data', frame);
+
+      // Check if it's a heartbeat packet
+      if (frame.command === COMMANDS.HEART_BEAT) {
+        this._lastHeartbeat = new Date();
+        return;
+      }
+
+      // Atempt to convert to JSON
+      let parsedData;
+
+      try {
+        parsedData = JSON.parse(frame.payload.toString('ascii'));
+      } catch (_) {
+        // Not JSON data
+        return;
+      }
+
+      if ('dps' in parsedData) {
+        // State update event
+        this._state = {...this._state, ...parsedData.dps};
+        this.emit('state-change', this._state);
+      }
+    });
   }
 
   private _handleSocketError(error: Error): void {

src/device.ts

@@ -1,3 +1,8 @@
+// Polyfills
+/* eslint-disable import/no-unassigned-import */
+import 'core-js/stable';
+import 'regenerator-runtime/runtime';
+
 import Device from './device';
 
 import * as Constants from './lib/constants';

src/index.ts

@@ -23,6 +23,23 @@ class Messenger extends EventEmitter {
     return frame;
   }
 
+  splitPackets(p: Buffer): Buffer[] {
+    const packets: Buffer[] = [];
+
+    const empty = Buffer.from('');
+
+    while (!p.equals(empty)) {
+      const startIndex = p.indexOf(Buffer.from('000055aa', 'hex'));
+      const endIndex = p.indexOf(Buffer.from('0000aa55', 'hex')) + 4;
+
+      packets.push(p.slice(startIndex, endIndex));
+
+      p = p.slice(endIndex, p.length);
+    }
+
+    return packets;
+  }
+
   decode(packet: Buffer): Frame {
     this.checkPacket(packet);
 
@@ -47,9 +64,9 @@ class Messenger extends EventEmitter {
     // Adjust for messages lacking a return code
     let payload;
     if (returnCode === 0) {
-      payload = packet.slice(HEADER_SIZE, HEADER_SIZE + payloadSize - 8);
-    } else {
       payload = packet.slice(HEADER_SIZE + 4, HEADER_SIZE + payloadSize - 8);
+    } else {
+      payload = packet.slice(HEADER_SIZE, HEADER_SIZE + payloadSize - 8);
     }
 
     // Check CRC